A wireless communication system, made up of a transmitting end, a receiving end and a wireless channel, transmits various signals using electromagnetic waves. At present, wireless communication systems have gradually evolved from the first, second, third, and fourth generations to the fifth generation (5G), and more types of wireless communication systems may emerge in the future. With developments in the technology, wireless communication systems are becoming more and more competent in supporting -multi-user transmissions. During the multi-user transmissions, interference between different users also appears. Regardless of whether the system is time division, frequency division, space division or code division, the presence of multi-layer user data results in interference between user data of different layers, and the interference may affect the restoration of signals at the receiving end. Therefore, there is increasing need for interference cancellation in wireless communication systems.